body {
    width: 100%;
    min-width: 320px;
    max-width: 640px;
    margin: 0 auto;
    font-size: 14px;
    font-family: -apple-system, Helvetica, sans-serif;
    color: #666;
    line-height: 1.5;
    background-color: gray;
    height: 2000px;
}
a {
    color: #666;
    text-decoration: none;
}
ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
img {
    /* 去出图片空白缝隙 */
    vertical-align: middle;
}
.app {
    height: 45px;
}
.app ul li {
    float: left;
    height: 45px;
    background-color: #333333;
    text-align: center;
    line-height: 45px;
    color: #fff;
}
.app ul li:nth-child(1) {
    width: 8%;
}
.app ul li:nth-child(1) img {
    width: 10px;
}
.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img {
    width: 30px;
/* 大图片与基线对齐 */
    vertical-align: middle;
}
.app ul li:nth-child(3) {
    width: 57%;
}
.app ul li:nth-child(4) {
    width: 25%;
    background-color: #f63515;
}
/* 搜素 */
.search-wrap {
    height: 44px;
    position: fixed;
    overflow: hidden;
    min-width: 320px;
    max-width: 640px;
    width: 100%;
}
.search-btn {
    position: absolute;
    top: 0;
    left: 0;
   
    width: 40px;
    height: 44px;
}
.search-btn::before {
    content: '';
    display: block;
    width: 20px;
    height: 18px;
    background: url(../images/s-btn.png) no-repeat;
    background-size: 20px 18px;
    margin: 14px 0 0 15px;
}
.search-login {
    position: absolute;
    top: 0;
    right: 0;
    width: 40px;
    height: 44px;
    
    color: #fff;
    line-height: 44px;
}
.search {
    position: relative;
    height: 30px;
    background-color: #fff;
    margin: 0 50px;
    border-radius: 15px;
    margin-top: 7px;
}
.jd {
    width: 20px;
    height: 15px;
    position: absolute;
    top: 8px;
    left: 13px;
    background: url(../images/jd.png) no-repeat;
    background-size: 20px 15px;
}
.jd::after {
    /* 这个定位也是search */
    position: absolute;
    top: 0;
    right: -8px;
    content: '';
    display: block;
    width: 1px;
    height: 15px;
    background-color: #ccc;
}
.suo {
    position: absolute;
    top: 8px;
    left: 50px;
    width: 18px;
    height: 15px;
    background: url(../images/jd-sprites.png) no-repeat -83px 0;
    background-size: 200px auto;

}
.slider img {
    width: 100%;
}
/* 品牌日 */
.brand {
    /* 盒子不要 */
    overflow: hidden;
    border-radius: 10px 10px 0 0;
}
.brand div {
   width: 33.33%;
   float: left;
}
.brand div img {
    width: 100%;
}
/* 导航栏 */
nav a {
    float: left;
    width: 20%;
    text-align: center;

}
nav a img {
    width: 40px;
    margin: 10px 0;
}
nav a span {
    display: block;
}
nav {
    padding-top: 5px;
    /* 减掉多余部分，在这里类似于清除浮动 */
    overflow: hidden;
}
/* 新闻模块 */
.news {
    margin-top: 10px;
}
.news img {
    width: 100%;
}
.news a {
    float: left;
    /* css3盒子模型 */
    box-sizing: border-box;
}
.news a:nth-child(1) {
    width: 50%;
}
 .news a:nth-child(2) {
    width: 25%;
    border-left: 1px solid #666;
}
.news a:nth-child(3) {
    width: 25%;
    border-left: 1px solid #666;
} 
/* 清除浮动 */
.clearfix:before, .clearfix:after {
    display: table;
    content: "";
}
.clearfix:after {
    clear: both;
}
.clearfix {
    *zoom: 1;
}
.content {
    margin-top: 10px;
    float: left;
    background-color: pink;
    width: 100%;
    height: 42px;
    color: skyblue;
    font-size: 30px; 
    text-align: center;
    line-height: 42px;
}
.f img {
   width: 100%;
}
.f a {
    float: left;
    box-sizing: border-box;
}
.f a:nth-child(n+1) {
   width: 50%;
}
.j img  {
    width: 100%;
}
.j a {
    float: left;
    box-sizing: border-box;
}
.j a:nth-child(n+1) {
    width: 25%;
}
